Tcas
 

hey guys...

I'm just a newly minted ATC and just want to ask a question on the flight deck operation of TCAS. I'm aware of how it all works, but want to know do u guys turn the RA's off at a certain point in approach? or a certain height? or is it purely on the captains discretion? i'm sure u wouldn't want a descend RA at 1000ft.... just wondering...
cheers..

Firstly I fly A319/320 so the tech bits may vary with other types, but, from the tech manual...

RA/TA is the normal position, TA only used in case of a/c degraded performance (eng failed etc) or approach on closely spaced parallel runways.

Some advisories are inhibited depending on a/c altitude:
1. All intruders flying below 380ft agl when own altitude below 1700ft agl
2. All RA below 1100ft in climb and 900ft in descent. In this case RA's converted to TA's
3. Descend type advisory below 1200ft agl at take off or 1000ft agl in approach
4. Increase descent RA below 1450ft agl
5. All TA aural messages below 500ft agl.

Hope this helps you

try this link

http://www.arinc.com/downloads/tcas/tcas.pdf

GR

Our TCAS has a RA-inhibit below ca900ft Radio height.

Thanks guys... much appreciated..:ok: